Cleaning exhaust system
 

Replacing the egr gasket on my car and just wondered if anyone ever cleaned their exhaust system. I was thinking a water flush after the engine so that everything gets flushed out through the rear exhaust, this would also rinse the catalytic converter. Then I would crank over the engine and give a couple strong revs and then maintain a steady rpm to dry/blow everything out. Or is this a really stupid idea?

Just guessing that if it did wonders there would be aftermarket adapters for quick connecting of a garden hose to do it being sold. Also thinking that if it did not move the water fast enough the pressure would find the weakest point in the exhaust system to relieve the pressure.

I do it with my diesel at the car wash to remove soot,I've done it to glass pack mufflers to break up the wadding.

The soot cat is a dead ended element. Its made of porous ceramic, which allows gasses to pass, but traps soot particles. If you do a hard run at high rpm, it will catalyze the soot. Thats the only way I know to clean it. Even if water could pass through, the soot would likely remain.

no mine is a 83 exempt

Just realized you're talking about a gasser. In that case, it's really wrong to do this. There's really not much to wash out in the exhaust, and you could damage the O2 sensors.

Water really won't clean anything out to any great degree.

EGR passages do sometimes clog because they are small and exhaust flowing through them is relatively cool. The cool exhaust gas allows hydrocarbons / oil to condense and stick to the passages.

A full exhaust system is large and runs at a much higher temp if the engine is running properly.